Heat generating devices, such as power semiconductor devices, may be coupled to a heat spreader to remove heat and lower the maximum operating temperature of the heat generating device. In some applications, cooling fluid may be used to receive heat generated by the heat generating device by convective thermal transfer, and remove such heat from the heat generating device. For example, jet impingement may be used to cool a heat generating device by directing impingement jets of coolant fluid onto the heat generating device or a target surface that is thermally coupled to the heat generating device. Additionally, jet impingement may also be combined with two-phase cooling, where the heat generating device is cooled by the phase change of the coolant fluid from a liquid to a vapor.
The coolant fluid flowing on the target surface may have regions of high fluid velocity, and regions of low fluid velocity. Coolant fluid flowing in the regions of high fluid velocity may not change phase to a vapor, but rather provide single-phase heat transfer, while coolant fluid flowing in the regions of low fluid velocity tends to boil and change to a vapor.
Accordingly, a need exists for alternative jet impingement, two-phase cooling apparatuses that take advantage of the high fluid velocity regions and the low fluid velocity regions of coolant flowing on a target surface after impingement.